docs: def wait(self, timeout=None):
          # type: (Optional[int]) -> None
          """Wait on the long running operation for a specified length
          of time. You can check if this call as ended with timeout with the
          "done()" method.
  
          :param int timeout: Period of time to wait for the long running
           operation to complete (in seconds).
          :raises CloudError: Server problem with the query.
          """
          if self._thread is None:
              return
          self._thread.join(timeout=timeout)
          try:
              # Let's handle possible None in forgiveness here
              raise self._exception  # type: ignore
          except TypeError: # Was None
              pass